I've read several fairly old posts that recommend displaying images with a slightly smaller height to allow for status bars, running title headers, etc, on many reader screens, and display for a height of approximately *720 ~ 760 px*. This is intended to keep the bottom portion of the image from being cut off.

So if you were using an image 600 px wide by 800 px high, you would effectively reduce display of the image by 10%. That sure seems like a lot.

Is this still a good practice to follow? Do most reader screens really use that much space to show status bar, etc? Do most reading apps/software follow the same ratio?

Inquiring minds want to know... (well, my inquiring mind, anyway. I don't know if I have company in this question.)

I think 720 is too much for most readers. 760 is more reasonable. Reading apps are often on touch screen devices so the status bar can generally be removed to be reinstated with a touch of the screen. Too large an image will generally be shrunk by the display program so the aspect ratio is more important than the actual pixel size. Today with higher resolution screens and some readers offering a zoom feature it is likely best to go with a bigger display and let it be shrunk. On most devices using an SVG wrapper around the image will guarantee a good fit.

I thing trying to match the available screen space is rather pointless. You can never be sure what the size of these elements, plus possible user-defined margin and whatnot will be. And worse, some users like reading in landscape orientation. I say use a "good enough" size and let the readers resize if needed.

My reader can be set with or without status bar, with or without headers... but it has some minimal margin that cannot be overriden.